/Engine/Plugins/Runtime/GameplayAbilities/Source/GameplayAbilities/Public/GameplayEffectAggregator.h
Works backwards to calculate the base value. Used on clients for doing predictive modifiers
float ReverseEvaluate ( float FinalValue, const [FAggregatorEvaluateParameters](API\Plugins\GameplayAbilities\FAggregatorEvaluateParameters) & Parameters ) const